[PATCH v3 3/3] kasan: arm64: support specialized outlined tag mismatch checks

[Peter Collingbourne]

On Wed, Jan 20, 2021 at 4:41 AM Will Deacon <will at kernel.org> wrote:
>
> On Tue, Dec 08, 2020 at 05:49:07PM +0000, Catalin Marinas wrote:
> > On Wed, Dec 02, 2020 at 09:12:24PM -0800, Peter Collingbourne wrote:
> > > By using outlined checks we can achieve a significant code size
> > > improvement by moving the tag-based ASAN checks into separate
> > > functions. Unlike the existing CONFIG_KASAN_OUTLINE mode these
> > > functions have a custom calling convention that preserves most
> > > registers and is specialized to the register containing the address
> > > and the type of access, and as a result we can eliminate the code
> > > size and performance overhead of a standard calling convention such
> > > as AAPCS for these functions.
>
> [...]
>
> > >  arch/arm64/include/asm/asm-prototypes.h |  6 ++
> > >  arch/arm64/include/asm/module.lds.h     | 17 +++++-
> > >  arch/arm64/lib/Makefile                 |  2 +
> > >  arch/arm64/lib/kasan_sw_tags.S          | 76 +++++++++++++++++++++++++
> > >  mm/kasan/tags.c                         |  7 +++
> > >  scripts/Makefile.kasan                  |  1 +
> >
> > I can try to queue the series but this patch would need an ack on the
> > kasan changes.
> >
> > (also, it may conflict with linux-next which renames tags.c to sw_tags.c
> > but that's trivial)
>
> Looks like this didn't land for 5.11. Peter -- please can you send a rebased
> version (on -rc4) so that I can queue it for 5.12?

Sorry for dropping the ball on this -- I've sent out a rebased v4 that
should be ready to go into 5.14 -- I guess it's too late for 5.13.

Peter